WEDNESDAY, May 7, 2014 (HealthDay News) -- E-cigarettes may not
be as harmless as they initially seemed. New research suggests that
e-cigarette vapor produces tiny particles that users suck deep into
their lungs, potentially causing or worsening respiratory
diseases.

The particles are of comparable size to those contained in
cigarette smoke, and as many as 40 percent of them reach the
deepest part of the lungs when inhaled, said Jonathan Thornburg,
lead investigator and a senior research engineer at RTI
International, a North Carolina research institute.

That means if the particles turn out to be harmful, they'll be
causing damage throughout the lungs.

"These small particles have a high surface area-to-volume
ratio," Thornburg said. "When they deposit in your lungs, it makes
it easy for whatever chemicals are in them to dissolve into your
lung tissue." Those chemicals potentially could cause or worsen
respiratory problems such as asthma or bronchitis.

In its review of emissions from two types of e-cigarettes,
Thornburg's team did not find any toxic substances in the vapor
produced by the devices.

"Everything we found was what the [U.S. Food and Drug
Administration] and others generally regard as safe," he said,
noting that the cancer-causing agents produced by burning tobacco
are not present in e-cigarettes.

But another new study raises the possibility that the liquids
used to produce e-cigarette vapors could contain carcinogens or
harmful ingredients,
The New York Timesreports.

The study found formaldehyde, a known carcinogen, in overheated
vapor produced by high-power e-cigarette devices known as tank
systems, the newspaper reported. These systems are larger devices
than typical e-cigarettes, and are designed to vaporize liquid
nicotine quickly to give users a bigger nicotine kick.

These studies provide even more impetus for the FDA's recent
proposal to begin regulating e-cigarettes as tobacco products, said
Dr. Norman Edelman, senior medical advisor for the American Lung
Association.

"We certainly don't believe e-cigarettes are a safe
alternative," Edelman said. "The question is whether it's a safer
alternative, and we believe those results aren't in yet. This is a
tobacco product and should be regulated by the FDA as all tobacco
products should."

Thornburg and his colleagues tested the vapor from e-cigarettes
using a new smoking machine built to replicate the physical
experience of a 14-year-old boy using one of the devices.

They first tested an e-cigarette liquid designed to create a
tobacco flavor. That liquid produced particles about 184 nanometers
in size. A second liquid -- this one with a fruit punch flavor --
produced particles about 270 nanometers in size. Those are within
the same range as the particles in cigarette smoke, according to
Thornburg.

The researchers also found that 47 percent of the inhaled
emissions deposited in the lungs, with nearly all of these
particles reaching the deepest part of the lungs.

The remaining 53 percent of the emissions, when exhaled, create
a potential source of secondhand exposure to people nearby, the
study authors said.

The main ingredients found in the e-cigarette liquids are
glycerin and glycol ethers, which are used as the liquid carrier
into which all of the nicotine, flavorings and preservatives easily
dissolve, Thornburg said. Those substances are not considered
harmful.

Other ingredients included nicotine, the preservatives BHA and
BHT, and chemicals that create the taste of caramelized sugar and
the scent of citrus.

"It's unknown whether these chemicals are harmful if you inhale
them," Thornburg said. "A lot of the chemicals are considered safe,
but that's from an ingestion perspective, not inhalation," he
noted.

According to Thomas Kiklas, CFO of the Tobacco Vapor Electronic
Cigarette Association, "All constituents [of e-cigarettes] have
been in the U.S. food supply for generations and all are approved
by the EPA/FDA for human inhalation and use dermally."

Kiklas contends, "The e-cig has and is being used by millions of
Americans. There have been billions and billions of uses without a
single incidence of harm."

Thornburg said nicotine researchers need to come together and
agree on a set of standards for researching e-cigarettes, given
that there are so many different liquids and devices available.

"Each combination could create a unique exposure that could
impact the user as well as bystanders," he said. "With so many
different potential combinations, we really need standardized
methods for conducting the research with the devices we use and
some liquids we use, so all of the research will be
comparable."

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

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